Latest Cretaceous mosasaurs and lamniform sharks from Labirinta cave, Vratsa district (nortwestern Bulgaria): a preliminary note

Jagt, John W. M. (2006)
(mosasaurs, lamniform sharks, Maastrichtian, Bulgaria, scaphitid ammonites, echinoids, stratigraphy)

The Middle Cenomanian basal series of Planinica, western Serbia

Rabrenović, Dragoman (2002)
(Late Cretaceous, Middle Cenomanian, clastics, ammonites, brachiopods, echinoids, Planinica, western Serbia)

The Cretaceous/Paleogene (K/Pg) boundary in the Mezdra and Lyutidol syncline, Vratsa District (West-Fore Balkan, Bulgaria)

Jolkičev, Nikola (2006)
(cretaceous/Paleogene boundary, Maastrichtian strata, nannofossils, foraminifers, inoceramids, ammonites, echinoids, West Fore Balkan, Bulgaria)